function xpathFirst(p, c)
	{
	return document.evaluate(p, c || document, null, XPathResult.ANY_UNORDERED_NODE_TYPE, null).singleNodeValue;
	}
function xpath(query, element)
	{
		var element = (element == null) ? document : element;
		return document.evaluate(query, element, null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
	}